The operation of heavy mechanical equipment such as large tractors generates considerable heat in the engines of the equipment, which must be efficiently dissipated to prevent damage to the engine. This is generally accomplished by coolant-based radiator systems, in which a pump circulates coolant through tubes in a radiator. Air cools the tubes and, hence, the coolant is then pumped through various engine components, e.g., an engine oil cooler, to cool these components.
The air that cools the tubes is blown past the tubes by a cooling fan located either just in front of or just behind the radiator. The cooling fan in turn is rotated by a motor which, as understood herein, can be a hydraulic motor that is actuated by oil which has been pressurized by a hydraulic pump.
Regardless of the particular type of motor used, however, the present invention understands that space inside an engine compartment of a heavy vehicle is limited, particularly in the axial (fore-and-aft) dimension. To reduce the amount of space required in the axial dimension by a cooling system, many existing systems minimize the size of the motor that rotates the fan. Unfortunately, minimizing the size, at least in the axial dimension, of the cooling fan motor can result in sacrificing power and/or efficiency. In either case, the cooling capacity and reliability of the system can be reduced. Fortunately, the present invention recognizes that it is possible to provide a cooling fan of adequate size and power, while minimizing the space in the axial dimension required by the cooling system